Electrode support



Aug 15 1950 J. J. AAKJER Erm. 2,518,848

ELECTRODE SUPPORT Filed Jan. l0, 1947 2 Sheets-Sheet 1 INVENTORS awww ATTORNEY Patented Aug. 15, 1950 UNITED STATES PATENT OFFICE ELECTRODE SUPPORT Application January 10, 1947, Serial No. 721,428

13 Claims. (Cl. Z50-27.5)

This invention relates to electrical devices, such as electronic tubes, and more particularly, to a construction whereby an electrode, and especially the anode, is rigidly supported.

The principal object of our invention, generally considered, is to reduce the cost of the anode seal assembly, when manufacturing electronic devices, including thyratrons, rectifiers and similar power tubes, adapting them for manufacture by standard receiving-tube practice, and especially in connection with the placing and support of the normally upper electrode or anode in such devices.

Another object of our invention is to support an electrode in a vitreous envelope or bulb by placing a piece of glass tube over the electrode lead, heating the outer end thereof to form a bead on said lead, inserting the beaded end in an aperture in a glass bulb or envelope, and sealing the beaded portion in said envelope so that the electrode extends from said seal inside the bulb.

A further object of our invention is to seal electrodes, more particularly such adapted to function as anodes in electronic devices, into enclosing envelopes by fitting a glass tube over each lead, supporting the electrode7 lead, and tube, enclosing with a pierced glass bulb or envelope so that the upper end of the lead passes through the aperture in said bulb formed by piercing, and in which the upper end of the tube closely ts, and heating to effect a seal between the apertured portion of said buib, said tube, and said lead.

' Other objects and advantages of the invention, relating to the particular arrangement and construction of the various parts, will become apparent as the description proceeds.

Referring to the drawing:

Figure 1 is an elevational view, partly in vertical section, of an electrical device embodying our invention.

Figure '2 is an enlarged vertical sectional view, with parts in elevation, showing the upper portion of said device during the process of manufacturing.

Figure 3 is a view corresponding to Figur@ 2, showing the device after the seal, initiated in accordance with Figure 2, has been effected.

Figure 4 is a view corresponding to Figure 3, but showing a modication.

Figure 5 is a view corresponding to Figure 3, but showing another embodiment of our invention.

Figure 6 is a view corresponding to Figure 3, but showing a further embodiment.` i

Figure 7 is a view corresponding to Figure 2, but showing an additional embodiment.

Figure 8 is a transverse sectional view on the line VIII-VIII of Figure 7, in the direction of the arrows.

Referring to the drawing in detail, and iirst considering the embodiment of our invention illustrated in Figures 1, 2, and 3, there is shown an electrical device Il, which may be a power industrial control tube manufactured and sold under the trade name thyratronj although our invention is adapted for use in the manufacture of other electronic devices including rectiers. We, therefore, do not wish to be limited to the details illustrated.

The device of Figure 1 comprises a vitreous or glass envelope I2 enclosing a coiled electrode I3 adapted to function as a cathode, an electrode I4, which may be :dat and relatively heavy, as illustrated, adapted to function as an anode, and a control grid I5. The electrode I3 is supported in a conventional manner, as from a nare tube I6 sealed to the envelope I2 in the usual manner, after which said envelope is based as indicated at I'I. The grid is also supported in a conventional manner from the flare tube I6.

The electrode Il, in the present embodiment, is supported in accordance with our invention, so as to hold it rigidly in place from the upper, relatively large, or generally spherical part of the envelope, or that opposite the flare tube IS, thereby preventing it from getting out of alignment, or maladjusted with respect to the associated electrodes. After securing to the envelope, in a manner which will subsequently be disclosed, the lead I3 0f said electrode is electrically connected to a contact cap I9, completing the device.

In accordance with the embodiment of Figures 2 and 3, the electrode or anode-functioning element I4, here shown as a iiat disk, has directly secured thereto, as by welding, soldering or threading, a lead section which is shown as comprising a fairly or relatively stiff portion 2l, formed of nickel-iron alloy. To the outer end of this portion is welded, as indicated at 23, a conductor 24 which is desirably formed of thin dumet or other exible material which satisfactorily seals through the glass employed. In the present embodiment, dumet is preferred, as it is intended to use soft glass, but we are not limited to this.

Over the lead I8 is placed a piece of tubing or sleeving 25, desirably formed of lead glass, and its outer end is heated to form a bead 26 on the lead i3. The tubing is of a size desirably fitting the nickel-iron portion 2| as closely as possible. The Weld knot 23 may or may not be imbedded in the glass bead 26 formed. If formed as illustrated the inner end of the iiexible conductor 24 is encircled by the tube 25, but spaced from the inner surface thereof.

A pierced bulb l2 is now used, that is one With an aperture 2l formed in its normally upper or generally spherical portion, said aperture being of a size to receive a portion of the bead 26, but not allowing the tubing 25 to pass entirely therethrough. The assembled electrode and connected tubing may be held in place in any desired manner,V as by means of a support 23, While the bulb I2 engages the bead 2, as illustrated in Figure 2.

Fires 23 are then directed on the edge of the bulb around the aperture 2l and the bead 2,6, until the parts are consolidated as illustrated in Figure 3.

An anode-lead-bulb assembly, in accordance pleted bulb, will not ordinarily appreciably disturb the relationship of the anode with respect to the other parts including the relatively-distant bulb Wall, as contrasted with previous constructions in which the anode lead did not have any surrounding tube or sleeve to limit bending thereof.

Referring now to the embodiment of our invention illustrated in Figure 4, there is shown a construction identical with Figure 3, except that the tube 25a extends very close to the electrode Ma, so as to even more closely limit movement oi said electrode. This construction prevents the possibility of the electrode canting on its lead or moving bodily toward the enclosing envelope to any substantial extent. However, it is desirable that it does not actually touch the electrode, to thereby avoid undesired conduction of heat therefrom to the tube. A clearance of about als of an inch is sulcient. The lead 18a may be as in the rst embodiment or formed of dumet or small Wire.

Referring to the embodiment of our invention illustrated in Figure 5, there is shown a construction similar to Figure 3, except that movement of the electrode 14h is still further restricted by after assembling heating the end oi the tube 2th adjacent thereto, to cause it to consti-ict very close about the lead portion 2lb, as indicated at Si, While not .however actually fusing thereto. rlhus, the tube 25b is formed at its inner end with a portion having an interior diameter closely corresponding with the. diameter of the lead portion 2lb. f

Figure 6 illustrates a form identical with Figure 5, except that the lead portion 2 le is shown formed of dumet or other similar small Wire. Rigidity is obtained by the extending and restricting of the tube 25, as in the embodiment of Figure 5.

Figures 7 and 8 illustrate another embodiment of our invention in which the electrode ldd is connected to the envelope ld, Without previously having its rigidifying tube 25d sealed to its lead iSd. In this connection, the lead may be constructed and connected to the electrode, as in any of the preceding embodiments, but the tube 25(i is positioned thereover and supported on the electrode with the desired clearance between the lower end oi the tube and the electrode Nid. Said electrode is then positioned on support d, the

tube 25d fitted over its lead 2id, and allowed to rest on a Washer or other spacing device 32, the bulb l2d fitted thereover so that the upper end of the tube 25d fits in an aperture 27d of the appropriate size illustrated, and res 29d are directed on the apertured portion of the bulb I2d and the upper end of the tube 25d to effect a seal. After the seal has been effected, the washer .'52 is removed and the device completed, as in the rst embodiment.

From the foregoing disclosure, it will be seen that We have provided a method of sealing a thin or non-rigid lead to a bulb, in such a Way that a relatively-heavy electrode on the lead is rigidly supported, yet the lead does not require prebeading and/or a stem construction. Such a construction, as here disclosed, is desirable because there are many cases Where it becomes necessary to 'seal a lead into a bulb, With the lead necessarily of thin non-rigid material of a composition to match thecoeiiicient or expansion of the glass. In the present embodiment, we prefer to use a soft glass, such as one designated lime or lead, because of economy, but any desired glass may employed.

Ii it is necessary for this lead to support an electrode, such as an anode for an electronic device, rigidly in a bulb, the disclosed method is desirable to stillen the lead and render the support rigid to prevent shifting with respect to associated electrodes. The disclosed method avoids the necessity for substituting stiffer material for that usually employed for leads, or Welding to the dumet, or other lead, a support member heavier or stiffer than the lead portion which passes through the glass.

Although preferred embodiments of our invention have been disclosed, it will be understood that modifications. may be made Within the spirit and scope of the appended claims.

We claim:

1. The method of making a bulb With an electrode rigidly supported therein, comprising fastening a lead to an electrode, tting a glass tube over said lead with only small clearance, tting said assembled parts into a bulb, with the outer end portion only of said tube in a bulb aperture, the tube extending inwardly from said outer end portion as a spaced stiiener around said lead and toward said electrode, with the electrode supported on the inner end of said lead, and heating the parts adjacent said aperture to seal them together for holding said electrode rigidly in place.

2. The method of making a bulb with an electrode rigidly supported therein, comprising fastening a lead to an electrode, fitting a glass tube over said lead with only small clearance, heating the end of said tube distant from said electrode to form a bead on said lead, fitting said assembled parts inside a bulb, with said bead in a bulb aperture, the tube extending inwardly from said bead as a spaced stiffener around said lead and toward said electrode, with the electrode supported on the inner end of said lead, and heating the parts adjacent said aperture to seal said bulb around and to said bead to hold said electrode rigidly in place.

3. The method of making abulb with an electrode rigidly supported therein, comprising fastening a lead to said electrode, fitting a glass. tube over said lead with only small clearance, fitting said assembled parts into a bulb, with the outer end of said tube in a bulb aperture and the tube extending inwardly from said bead as a spaced stiiener around said lead and toward said electrode, with the electrode supported on the inner end of said lead, and heating the parts adjacent said aperture to seal them together and hold said electrode in place.

4. The method of making a bulb with an electrode rigidly supported therein, comprising fastening 'a flexible lead to an electrode, tting a glass tube over said lead with only small clearance and of such a length that said lead extends therebeyond, depositing a spacing device between the lower end of said tube and said electrode, fitting the assembled parts into a bulb, with the outer end of said tube engaging said bulb adjacent an aperture, the lead extending therethrough, and the electrode extending inwardly therefrom, heating the parts adjacent said aperture to seal them together for holding said electrode rigidly in place, and removing said spacing device.

5. The method of making a bulb with an electrode rigidly supported therein, comprising fastening a lead to an electrode, fitting a glass tube over said lead, heating the end of said tube adjacent said electrode to cause it to contract closely about without sealing to said lead, tting the assembled parts into a bulb, with the other end portion only of said tube as the outer end portion in a bulb aperture and the tube extending inwardly from said outer end portion as a spaced stiifener around said lead and toward said electrode, and heating the parts adjacent said aperture to seal them together for holding said electrode rigidly in place.

6. The method of making a bulb with an electrode rigidly supported therein, comprising a fastening the stiff portion of a partly stiff and partly flexible lead to said electrode, fitting a glass tube over said lead with only smal clearance and with a part extending therebeyond, heating the end oi said tube distant from said electrode to form a bead on the ilexible portion of said lead, tting said assembled parts inside a bulb, with said bead in a bulb aperture and the tube extending inwardly from said bead as a spaced stiffener around said lead and toward said electrode, with the electrode supported on the inner end of said lead, and heating the parts adjacent said aperture to seal said bulb around and to said bead to hold said electrode rigidly in place.

7. The method of making a bulb with an electrode rigidly supported therein, comprising fastening a flexible lead to an electrode, tting a glass tube over said lead with only small clearance and of such a length that said lead extends therebeyond, depositing a spacing device between the lower end of said tube and said electrode, heating the end of said tube distant from said electrode to form a bead on said lead, fitting said assembled parts inside a bulb, with said bead in a bulb aperture and the electrode extending inwardly therefrom, heating the parts adjacent said aperture to seal said bulb around and to said bead to hold said electrode rigidly in place, and removing said spacing device.

8. The method of making a bulb with an electrode rigidly supported therein, comprising fastening a lead to an electrode, .iitting a glass tube over said lead, heating the end of said tube distant from said electrode to form a bead on said lead, heating the end of said tube adjacent said electrode to cause it to contract closely about said lead, fitting said assembled parts inside a bulb with said bead in a bulb aperture and the tube extending inwardly from said bead as a spaced stii- 6 ener around said lead and toward said electrode, with the electrode supported on the inner end of said lead, and heating the parts adjacent said aperture to seal said bulb around and to said bead to hold said electrode rigidly in place.

9. An electrical device comprising a vitreous envelope, a vitreous tube with one end sealed thereto and extending inwardly therefrom, a relatively flexible lead with only small clearance in said tube, sealed through said envelope and tube at the point of union, and an electrode on the inner end of said lead, said tube at its inner end being formed with a portion having an interior diameter closely corresponding with the diameter of said lead, whereby the support of said electrode is rigidied by said tube closely limiting movement of the encircled lead.

10. An electrical device comprising a glass envelope, a glass tube with one end sealed thereto and extending inwardly therefrom, a lead comprising a iiexible portion sealed to said envelope and tube at the point of union and with its inner end enclosed in, but spaced from the inner surface of, said tube, a stiffer portion extending from said inner end of the exible portion and closely encircled by said tube so that movement thereof is limited, and an electrode rigidly supported on the inner end of said stiier portion in place inside of said envelope.

1l. An electrical device comprising a glass envelope, a glass tube with an end sealed thereto and extending inwardly therefrom, a lead sealed through said envelope and tube at their point of union, the inner end of said tube being constricted to closely encircle said lead, and an electrode on the inner end of said lead, whereby the support of said electrode is rigidifled by said tube closely limiting movement of the encircled lead.

12. An electrical device comprising a glass envelope formed with a relatively large end portion, a glass tube with one end sealed to and extending inwardly from said end portion, a lead comprising a relatively flexible portion sealed to said end portion and tube at the point of union and with its inner end enclosed in, but spaced from the inner surface of, said tube, a stiffer portion of said lead extending from the inner end of said iiexible portion and closely encircled by said tube, and a ilat electrode spaced at a relatively great distance from said end portion, secured to the end oi said stiier portion, and positioned very close to the inner end of said tube, whereby the support of said electrode is rigidied by the tube closely limiting movement of the encircled lead.

13. An electrical device comprising a glass envelope formed with a relatively large end portion, a glass tube with one end sealed to and extending inwardly from said end portion, a relatively ilexible lead sealed to said end portion and tube at the point of union and closely encircled by said tube, and an electrode spaced at a relatively great distance from said end portion, secured to the end of said lead, and positioned very close to the inner end of said tube, whereby the support of said electrode is rigidied by the tube closely limiting movement of the encircled lead and preventing the possibility of the electrode canting on its lead or moving bodily toward said envelope to any substantial extent.

JENS J. AAKJER. WILLIAM J. KNOCHEL.

(References on following page) REFERENCES CITED Number The fo11owing references are of record in the fe of thrs patent. 1951913 UNITED STATES PATENTS 5 2,242,774 2,356,566 Number Name Date 1,815,762 Charlton July .21, 1931 1,951,612 Hunter, Jr Mar.. 20, 1934 Number 1,990,728 Etel et a1. Feb. 12, 1935 10V 219,395

Name *Date 1; Laico Dec. 17,1935.; Beggs Sept. 26, 1939 Bachman Apr.- 2, 1946 1 Brumley May 20., 1941 Clark et a1 Aug. 22, 1944 FOREIGN PATENTS Country Date Great Britain Ju1y 25 1924. 

